Chapter 2:NUTRITION

NUTRITION

Flash Review

  2.1 | CLASSES OF FOOD

            1) Food is necessary as a source of energy, to stay healthy and to grow.

            2) Food can be divided into seven classes, carbohydrates, proteins, fats, vitamins,   minerals, fibre and water substances required by our body.

            3) Nutrition is the process of obtaining and using nutrients.

      Carbohydrates

               1) Carbohydrates are compounds of carbon, hydrogen and oxygen. They supply most of our energy needs.

               2) Carbohydrates are found in foods such as sugars, starch, and cellulose.

               3) Sugar are the simplest form of carbohydrates. Sugar can be classified as simple sugar and complex sugars.The simplest form of sugars are glucose, fructose and galactose. More complex sugars are sucrose, lactose and maltose. Sucrose is found in sugar, honey, and fruits.

              4)  Starch is a more complex carbohydrate. Starch is found in rice and other cereals.

              5)  Glycogen is ‘animal starch’ and is found in meat.

              6) Our digestive system converts all forms of carbohydrates to glucose, except cellulose.

      Proteins

             1) Proteins are made of carbon , hydrogen, oxygen and nitrogen. Some proteins have sulphur and phosphorus.

             2) Proteins are built by combining smaller units of molecules known as amino acids.

             3) Our body makes some of these amino acids. The other amino acids are supplied by the food we eat.

             4) There are basically two types of proteins, animal proteins and vegetables proteins.

             5) Proteins are needed for the building of muscles, heart, bones and so on. They are also necessary in the repair and replacement of damaged tissues.Proteins are also used in formation of enzymes and hormones which are needed for the proper functioning of the body.

      Fats

1       1) Fats contain carbon, hydrogen and oxygen. However, compared with carbohydrates, fats have fewer oxygen atoms relative to the number of carbon and hydrogen atoms. Fats can exist in solid or liquid.

         2) Fats is stored under the skin and around the organs in our body

         3) Fats forms layer under the skin and help in preventing excessive heat loss from the body.

         4)Fats can act as protective layers covering certain organs such as the heart, kidneys and so on.

         5) Fats help in the absorption and transportation of fat soluble vitamins.

         6) Fats are made up of combination of fatty acids and glycerol.

   Vitamins

       1) Vitamins are organic substances which are necessary for the body to function properly. Only small amounts of vitamins are needed by the body.

       2)  All the vitamins are can  be classified into two types , water soluble(vitamins B and C) and fat soluble(vitamins A,D,E, and K)